Fold-out trailer with retractable wheel assembly

ABSTRACT

A trailer includes a trailer frame having a hitch. A stationary support base is joined to the trailer frame. Two supports are slidably guided on the support base toward and away from each other. A wheel assembly is mounted to an end of each of the supports remote from the other support such that a distance between the wheel assemblies varies with movement of the supports on the support base. A locking device selectively locks each support to the support base in a first position where the wheel assemblies are furthest from each other and a second position where the wheel assemblies are closer to each other.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is a continuation and claims priority ofapplication Ser. No. 16/708,047, filed Dec. 9, 2019, which is acontinuation of application Ser. No. 15/896,903, filed Feb. 14, 2018(which is now U.S. Pat. No. 10,501,133, issued on Dec. 10, 2019), whichis a continuation of application Ser. No. 14/961,450, filed Dec. 7, 2015(which is now U.S. Pat. No. 9,926,026, issued on Mar. 27, 2018), whichis a divisional of application Ser. No. 13/668,530, filed on Nov. 5,2012 (which is now U.S. Pat. No. 9,205,881, issued on Dec. 8, 2015),which is claims benefit of provisional application 61/555,292, filed onNov. 3, 2011, the contents of which are all hereby incorporated hereinin their entirety.

BACKGROUND

Trailers have been used for centuries. Covered wagons, perhaps a moremodern form of trailers given the history, provided covered living spaceduring travel. More recent times have rendered the “pop-up” or“fold-out” vehicle pulled trailer in which the trailer has a couplepositions, a compacted travel position and an expanded use position.Each of these trailers is part of a long existing desire for expandablecovered living space presented in a trailer form.

Co-extensive with the modern development of trailers has been thedevelopment of renewable and non-renewable energy sources. Early on,fuel consumption was relatively low and concern about over use was notprevalent. As fuel consumption rose and expense of fuel reached newlevels, society became interested in being more energy efficient. Thistrend expanded into an awareness of the need to protect the environmentfrom wasteful uses of fuel. Trailers large in travel profile are at oddswith fuel efficiency. In addition, large trailers are difficult to storeand transport.

SUMMARY

A trailer includes a trailer frame having a hitch. A first primaryplatform has a first major surface defining a first primary plane, afirst inside edge and a first outside edge. The first primary platformis pivotally supported by the trailer frame and can be disposed in afirst upright position wherein the first primary platform extendsupwardly from the first inside edge with the first outside edge beingelevated above the first inside edge. A second primary platform has asecond major surface defining a secondary primary plane, a second insideedge and a second outside edge. The second primary platform is pivotallysupported by the support frame on a side opposite the first primaryplatform and can be disposed in a second upright position wherein thesecond primary platform extends upwardly from the second inside edgewith the second outside edge being elevated above the second insideedge. A wheel assembly includes a stationary support base joined to thetrailer frame, two supports slidably guided on the support base towardand away from each other, and a pair of wheel assemblies. A wheelassembly is mounted to an end of each of the supports remote from theother support such that a distance between the wheel assemblies variesfrom an extended position to a retracted position with movement of thesupports on the support base. A distance between the wheel assemblies inthe extended position is greater than a distance between the wheelassemblies in the retracted position. Rotatable outwardly facingsurfaces of the wheel assemblies face in opposite directions and arefarthest from each other in the extended position are disposed outboardfrom the first inside edge and the second inside edge such that adistance between the outwardly facing surfaces is greater than adistance between the first inside edge and the second inside edge.

A trailer includes a trailer frame having a hitch. A stationary supportbase is joined to the trailer frame. Two supports are slidably guided onthe support base toward and away from each other. A wheel assembly ismounted to an end of each of the supports remote from the other supportsuch that a distance between the wheel assemblies varies with movementof the supports on the support base. A locking device selectively lockseach support to the support base in a first position where the wheelassemblies are furthest from each other and a second position where thewheel assemblies are closer to each other.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front perspective view of the fold-out trailer showing thetrailer in a fully-extended position.

FIG. 2 is a rear perspective view of the fold-out trailer in a fullyextended position showing the trailer with portions of the canopyremoved for clarity.

FIG. 3 is a schematic front elevational view of ground supports whichare selectively engageable with a ground surface.

FIG. 4 is a schematic top view of the ground supports of FIG. 3.

FIG. 5 is a perspective sectional view of fabric support connections ona wall assembly.

FIG. 5A is a perspective sectional view of fabric support connections ona floor platform.

FIG. 6 is sectional view of the layers of at least two fabric panelsmade out of two or more layers for forming a hinge.

FIG. 7 is a perspective view of an upper portion of the trailer having afirst embodiment for covering a flexible hinge.

FIG. 7A is a perspective view of an upper portion of the trailer havinga second embodiment for covering a flexible hinge.

FIG. 8 is a top plan view of the trailer in the extended position.

FIG. 9 is a perspective view of the trailer in a mostly folded travelingposition with a step assembly installed.

FIG. 10 is a side elevational view of the trailer in the extendedposition.

FIG. 11 is front elevational view of the trailer in the travelingposition and the tire and wheel assemblies retracted.

FIG. 12 is a front elevational view of the trailer in the travelingposition and the tire and wheel assemblies extended.

FIG. 13 is a schematic illustration of a first embodiment of aretractable wheel assembly.

FIG. 14 is a schematic illustration of the retractable wheel assembly ofFIG. 13 in an alternative position.

FIG. 15A is a bottom plan view of the trailer.

FIG. 15B is a top plan view of the retractable wheel assembly of FIG.13.

FIG. 15C is a perspective view of the trailer with parts removed.

FIG. 16 is a perspective view of a lock assembly in a first position.

FIG. 17 is a perspective view of the lock assembly in a second position.

FIG. 18 is a perspective view of the lock assembly in a first and secondposition.

FIG. 19 is a sectional view of trailer.

FIG. 20 is an enlarged view of a retractable pin of a locking devicewith other portions removed.

FIG. 21 is a top plan view of a second embodiment of a retractable wheelassembly with portions removed.

FIG. 22 is a perspective view of the second embodiment of theretractable wheel assembly of FIG. 21 with portions removed.

FIG. 23 is a rear elevational view of the second embodiment of theretractable wheel assembly with portions removed.

FIGS. 24 and 25 are perspective views of a variation of the secondembodiment of the retractable wheel assembly with portions removed.

FIG. 26 is a top plan view of a third embodiment of a retractable wheelassembly.

FIG. 27 is a perspective view of the third embodiment of the retractablewheel assembly of FIG. 26 with portions removed.

FIG. 28 is a perspective view of a ski assembly connected to thetrailer.

FIG. 29 is a perspective view of the trailer with a second embodiment ofstabilizing supports.

The figures now have been shown and will be described in clear detailenabling one of ordinary skill to make and use the present invention.Modifications can be made without departing from the spirit and scope ofthe invention.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

Aspects of the invention will be described with respect to fold-outtrailer 10 illustrated, for example, in FIGS. 1, 2 and 8-12. However, itshould be understood that trailer 10 is but one embodiment where aspectsof the invention can be incorporated on other folding or expandingtrailers, or on other forms of trailers that are not necessarily usedfor camping or even on equipment that is generally pulled by anothervehicle or device.

The trailer 10 as shown in the figures and described herein has somefeatures also present in the trailer described in U.S. Pat. No.7,967,369, the content of which is hereby incorporated by reference inits entirety. In the exemplary embodiment illustrated, the trailer 10includes a trailer frame 20, at least one primary folding platform 40,at least one wall assembly 70 and a retractable wheel assembly 200.These components cooperatively form a fold-out trailer 10 that has asmall profile when folded that can be used on both narrow and widepaths. Additionally, the trailer 10 has a large covered living/storagearea when in an expanded, camping position 14.

As illustrated in FIGS. 1 and 2, the trailer frame 20 can have a tongue22 joined to a hitch 24. The hitch 24 can, in turn, be joined to avehicle, such as a car or an all-terrain vehicle, or any othermotor-powered object that is configured to receive the hitch 24 and pullthe trailer 10. These components are of standard size, strength andmaterials as are found throughout the field of trailers. The tongue 22is joined to a stationary platform 28, which can be of any material ofsuitable size and strength. The stationary platform 28 forms a portionof the floor when the trailer 10 is in the expanded, camping position14. As such, the stationary platform 28 may be insulated or have a floorcovering, such as carpet. The stationary platform 28 can also includeone or several storage compartments 97 that are accessible through atleast one access door 99. The access door 99 can be located below thefloor of the trailer and/or on the side of the stationary platform. Thestationary platform 28 has a major surface 30 defining a stationaryplane 31, a plurality of side edges 32, a front edge and a back edge 36.The stationary platform 28 may be joined to and supported above anundercarriage 26. The trailer 10 includes at least one primary foldingplatform 40. The primary folding platform 40 has a major surface 42, aninside edge 44, an outside edge 46 to which ground supports 58 can beattached. In one embodiment as illustrated, there are two primaryplatforms 40. The inside edge 44 of the primary platform 40 is desirablyjoined to one side edge 32 of the stationary platform 28 via a hinge.Such hinge may be a stepped-up hinge, adding clearance for the wallassemblies 70. The ground supports 58, joined to the primary platform40, are selectively engageable with a ground surface, e.g., dirt, sand,tar, gravel, etc. In an advantageous embodiment shown in FIGS. 3 and 4,ground supports 58 are removably attached to edge 46 by way of at leasta plurality of projections 17 a and 17 b selectively engaging groundsupport plate 58. Projections 17 a and 17 b extend outwardly from theedge 46. Apertures 19 a and 19 b located in ground support plate 59 areconfigured with a first ends to receive enlarged heads 18 of projections17 a and 17 b and extending slots of size only to accept support posts19.

The primary platform 40 has a folded position 52 (FIG. 9) in which theplane of the platform 40 and stationary plane 31 are skewed planes,e.g., non-parallel or perpendicular. One skilled in the art can see howthe angle of the platform 40 to the stationary platform 28 directlyimpacts any “top heavy” issues and trunk size issues. In the foldedposition, the primary folding platform 40 is used as an outer-mostenclosure, enclosing some of the remaining components of the trailer,such as, for example, the secondary folding platform. The primaryplatform 40 has an extended position 54 (FIGS. 1 and 2) in which theplatforms 40 and stationary platform 28 are co-planar. That is, theprimary platform 40 forms a portion of the floor and as such may beinsulated or have floor coverings including carpet as desired. In oneembodiment, two primary platforms 40 are provided, one folding on eachside of the trailer 10.

Referring back to FIGS. 1 and 2, the trailer 10 also includes at leastone wall assembly 70 which may have at least one segment 72 and perhapswindows 98. In one embodiment there are two wall assemblies 70 and threewall segments 72 per wall assembly 70. The wall assemblies 70 form rigidsides to the fold-out trailer 10 when in an extended position 14. Eachwall segment 72 has a major surface 74 defining a segment plane 75, sideedges 76, a top edge 78 and a bottom edge 80. Side edges 76 of adjacentwall segments 72 are preferably joined via a hinge 56. Bottom edges 80of each wall segment 72 are preferably joined to one of the stationaryplatform 28 and the primary platform 40 via a hinge 81, which may be astepped up hinge as needed. Each wall assembly 70 desirably has anextended position 86 in which the assembly is perpendicular to both thestationary platform 28 and the primary platforms 40 and a foldedposition in which the segments 72 are each parallel to one of theprimary platforms 40 and the stationary platform 28. One or more of thewall assemblies 70 may have a door 82 for human ingress and egress.

Referring again to FIGS. 1 and 2, when the wall assemblies 70 are in anextended position 86, a canopy 96 extends therebetween so as to providea roof and/or walls, being secured to the wall segments 72. The canopy96 may further be secured to the primary platform 40. While the canopy96 may be attached when the wall assemblies 70 are in the foldedposition 84, such is not necessary. Struts 71 or other support structureextending between the wall assemblies 70 may be used to add structuralsupport to the canopy 96 in the extended position. In one embodiment,the canopy 96 is of a tent awning or marine grade fabric known in theart, such as, but not limited to, nylon and/or canvas. The fabric can bemade of a variety of suitable materials. For example, some fabriccharacteristics can include puncture-resistant, mildew-resistant andmold-resistant. The fabric can also include properties so as to haveultra-violet protection.

In an advantageous embodiment, the canopy 96 comprises an outer fabriclayer 96 a and an inner fabric layer 96 b, each of which are fixedlyconnected to the wall assemblies 70 from when the wall assemblies 70 arein the folded transport configuration of the trailer 10 to the extendedconfiguration where the wall assemblies 70 are oriented perpendicular tothe platforms 40. As illustrated in FIG. 5, trailer 10 can also includea plurality of fabric support connections 100 a and 100 b for outerfabric layer 96 a and inner fabric layer 96 b, respectively. The fabricsupport connections 100 a and 100 b extend along the edges 76 and 78 ofeach wall assembly 70 and extend along the edges 46 of the primaryplatforms 40. The fabric support connections 100 a and 100 b are spacedapart from each other so as to hold fabrics 96 a and 96 b away from eachother in the extended position 86 of the trailer 10 so as to trap airtherebetween and thereby provide an insulated roof and side walls.

In the embodiment illustrated in FIG. 5, the fabric support connections100 a, 100 b comprise an enlarged lateral edge 142 on each of the edgesof the fabrics 96 a, 96 b that is disposed in elongated slotted channels143 a, 143 b such that the fabric 96 a, 96 b extends out of the slot ofthe slotted channels 143 a, 143 b. The slotted channels 143 a, 143 b canbe integrally formed together from a single unitary body such as from asingle extrusion 144. In the embodiment illustrated for the wallassemblies, the extrusion 144 is L-shaped where slotted channel 143 afor the outer fabric 96A is disposed along the outer edge of the wallsegments 72 and a support portion 145 a of the extrusion 144 covers theouter edge of the wall segments 72 of the wall assemblies 70, while asupport portion 145 b of the extrusion 144 supports the slotted channel143 b for the inner fabric 96 b, which is disposed on inwardly facingsurfaces of the wall segments 72 of the wall assemblies 70. In anotherembodiment, the elongated slotted channels 143 a and 143 b are notintegral (i.e., formed of a single unitary body) but rather are separatepieces connected, if desired, by way of a fastener (herein a pluralityof pins 115 attached to the wall segments 72).

As illustrated in FIG. 5A, slotted channels 153 along the edge 46 forthe fabrics 96 a, 96 b are substantially similar to the slotted channels143 disposed on edges 76, 78 in that they are spaced apart from eachother and have slots, herein opening upwardly, with portions of thefabrics 96 a, 96 b extending therethrough, while enlarged end portions152 are retained therein. As with the slotted channels 143 disposed onedges 76, 78 the slotted channels 153 disposed along edges 46 can beseparate parts (as illustrated) secured to edges 46 of each of theplatforms 40 or integrally formed from a single unitary body.

At this point it should be noted the enlarged ends 142 of the fabrics 96a, 96 b inserted in the slotted channels 143 a, 143 b can be formed forexample from fabric tubing or awning rope, such as sold by Keder ofShenzhen, China.

In the illustrated embodiment in FIG. 1, side extrusion 144 does notextend continuously along edges 76 and 78, but rather comprises threesections. A first section 144A of the side extrusion 144 starts at oneof the side edges 76 of the wall assembly 70 and extends longitudinallythrough the top edge 78 of the wall assembly 70 until it encounters afirst end 56 a of the hinge 56. A second extrusion section 144B of theside extrusion 144 begins at a second end 56 b of the hinge 56 andcurves around to a first end 56 c of a different hinge 56. A thirdsection 144C of the side extrusion 144 starts at a second end 56 d ofthe second hinge 56 and slightly curves at top edge 78 and extendsdownwardly alongside edge 76. In other words, extrusion 144B is disposedalong the upper edge of the middle wall segment 72 of each of the wallassemblies 70, while extrusions 144A and 144C are disposed along theedges of the side wall segments 72 of each of the wall assemblies 70.

In one embodiment as illustrated in FIG. 1, the inner fabric 96 b and/orthe outer fabric 96 a is made out of or can include stretchable material140, such as, for example, a band. The stretchable material 140, shownin FIG. 1, can extend throughout the whole inner fabric 96 b, or it canbe just in a section of the inner fabric 96 b. This will preventstraining the two fabrics 96 a, 96 b as the wall assemblies 70 areraised and separated so as to form the enclosure. In one embodiment, thematerial of the inner fabric 96 b may be different than the material ofthe outer fabric 96 a. For example, the inner fabric 96 b may belightweight and allow moisture to transfer through it. In anotherconfiguration as mentioned above, both the inner fabric 96 b and theouter fabric 96 a can trap air inside for insulation, yet still allowfor moisture to travel through.

In one embodiment as illustrated in FIG. 6, hinges 56 are made out of atleast two flexible (e.g. fabric) panels 133 a and 133 b. In anadvantageous embodiment, one or more of the at least two flexible panelsare made out of two or more layers 135 a and 135 b. The layers 135 a,135 b can be sewn, bonded or otherwise joined together.

In another embodiment illustrated in FIGS. 1, 7 and 7A, flaps or covers114, 114A are provided so as to cover the hinges 56 where the fabricconnections 100A, 100B on the wall segments 72 are separated from eachother (because of the hinges 56 between the wall segments 72). Thecovers or flaps 114 help seal any open gaps that may exist between theends of the fabric connections 100A, 100B (herein extrusions 144A-144C).Portions of the covers or flaps 114 can be secured to the fabric 96 aand/or hinge 56 such as by bonding or sewing. If desired one end of thecovers or flaps 114, 114A can be loose and after configuration of thetrailer in the extended position, then the loose portion can be securedto the fabric 96 a or wall segment. In FIG. 7, cover 114 is secured tothe fabric 96A, while a loose portion can be removably secured to thewall segments 72 with suitable fasteners such as snaps, hook-and-loopfasteners and/or elastic bungee cords. In FIG. 7A, the cover 114A isformed from material of the hinge 56 and extends over an upper portionof the hinge 56 and is secured, in this embodiment non-removably, to thefabric 96 a. As described above, covers 114 and 114A can be separateelements or formed integrally as a single unitary body from fabric 96 aor the material forming hinge 56.

In one embodiment shown in FIG. 1, one or more receivers 116 can beprovided on the enclosure 108 such as provided on the outer fabric 96 athat runs all the way around the top panel 108 and accepts a segmentedrod 120, as typically found with outdoor tents. For instance, there canbe two such receivers. In one embodiment, a segmented rod 122 that snapstogether can be inserted in the receivers 116 to help hold the enclosure108 upright and prevent sagging of the fabric 96 a. The receiver 116 cancomprise one or more pockets, as illustrated, and/or spaced apart loops124.

In one embodiment, trailer 10 includes a rigid panel 109, as shown inFIG. 1. Rigid panel 109 extends above the inside edges 44 of the primaryfolding platform 40 and connects the inside edges 44 with the fabricsupport connections 100. The rigid panel 109 ensures that if pressurewere applied (i.e., by way of a human shoe or large item) against thesides of the fold-out trailer in the expanded position, the appliedpressure will not rip the fabric.

In one embodiment shown in FIGS. 1 and 8, a hooked fastener inside thetrailer 10 can be used to create a panel board 119 so that the wallsegments 72 and the hinges 56 will no longer be independent, but will betied together as a single wall structure for extra support. In oneembodiment, panel board 119 is held in place by way of at least aplurality of supports 121.

In the embodiment shown in FIG. 9, the trailer 10 includes solar panels128 underneath the cover of the top panel 118 on the inward facing sideof the trailer 10. The top panel 118 may be removable. That is, the toppanel 118 may be wholly or partially removable. In an advantageousembodiment, the solar panels 128 are operably connected to a battery 129in order to store the energy obtained by the solar panels 128 for use,for example, during the night. If desired, the solar panels 128 can bearranged to work even when the trailer 10 is in the traveling or foldedposition 12.

The front cover 90 may be positioned adjacent to the tongue 22. Thefront cover 90 provides an initial wind engaging surface when travelingwith the trailer in the folded position 12 and therefore is intended tohave an aerodynamic exterior shape. The cover 90 further defines an areafor storage, which may include items such as propane tanks. The frontcover 90 may engage the stationary platform 28 and primary platforms 40when the primary platforms 40 are in a folded position 52 as illustratedin FIG. 9. Structure of the front cover 90 may engage the stationaryplatform 28 and may be removably joined to the wall assembly 70 when thewall assembly 70 is in the extended position 86. In either engagementscenario, an area for storage is defined therein.

A back cover, not shown, engages the stationary platform 28 and isengageable with the primary platforms 40 when the primary platforms 40are in the folded position 52. The back cover helps maintain anycontents inside the trailer 10 when the primary platforms 40 are in thefolded position and further can inhibit suction within the trailer 10during travel. The back cover may be hinged or otherwise arranged toengage the stationary platform 28 and a ground surface, such as sand,dirt, water, gravel, vegetation, etc., when the back cover is in anextended position. The back cover may be shaped as a ramp for easyloading and unloading of the trailer. Alternatively, the back cover mayprovide steps to climb into the trailer 10.

In an advantageous embodiment shown in FIGS. 9 and 10, the trailer 10includes steps 130 for entering and exiting the trailer 10 through thedoor 82. The steps 130 comprise L-shaped brackets 132 that slide intocorresponding receivers 134. The brackets 132 are skewed outwardly inorder to provide stability. The steps 130 can also utilize an adjustablesupport 136 that extends downwardly. Panels 131 are removably joined tothe brackets 132 to form the steps 130.

Referring to FIG. 10, a winch assembly 235 is provided to lift and lowera wall assembly 70, herein the front wall assembly. The winch assembly235 includes a winch 266, an optional pulley 272 and lift cable 274attached at a remote end to the wall assembly 70. FIG. 10 illustratestwo winch configurations. In a first exemplary configuration, the pulley272 is mounted in a lower position 280, while in a second exemplaryconfiguration the winch assembly 235 includes a mast 270 to support thepulley 272 at a higher location to increase leverage. The winch 266 canbe an electric or manual winch. In an alternative embodiment, the winch266 can be located at position 280.

The winch assembly 235 can also include and a mast 270 with a deployablepulley 272 so that a larger angle is created with cable 274 to lift thewall assembly 70. Supports 71 can be provided inside (or outside) tosupport the wall assembly 70 in the vertical position. Such supports 71can be located along the roof (FIG. 2) and/or along side(s) of thetrailer 10 (FIG. 10).

A latch 268 can also be used to hold the wall assembly 70 vertically inthe extended position. The latch 268 can take any number of forms. Forinstance, the latch 268 can comprise a plate 271 secured to the wallassembly 70 so as to raise and lower with the wall assembly 70. Theplate 271 can include an aperture. When the wall assembly 70 is in theupright position of FIG. 10, the aperture would be disposed proximate afixed, support structure (for example a portion of front cover 290) suchthat a pin disposed in the aperture also engages the fixed supportstructure so as to inhibit movement of the plate 271 away from the fixedsupport structure.

In one embodiment shown in FIGS. 11 and 12, another aspect furthercomprises a retractable or adjustable wheel assembly 200 that varies thespacing between a plurality of wheels 202 used to maneuver the trailer10. Schematic illustrations of a first embodiment of the retractablewheel assembly 200A are shown in FIGS. 13 and 14. The retractable wheelassembly 200A includes a support assembly 204, a guide assembly 206 anda link assembly 208. The support assembly 204 has a support base 210rigidly connected to the frame of the trailer 10 in the traveling andthe camping positions 12, 14. The support assembly 204 also has at leasta plurality of support plates 212 that move relative to the support base210. In an extended position of the retractable wheel assembly 200 shownin FIG. 12, the plurality of support plates 212 is spaced apart from oneanother (FIG. 13). As the retractable wheel assembly 200 moves toward aretracted position 214 shown in FIG. 11, the plurality of support plates212 move toward one another so that the ends closest to the wheels 202are aligned with each lateral end of the support 210 (FIG. 14). In theembodiment illustrated, support plates 212 are in the same plane.

The outer ends of the support plates 212 are connected to the wheels 202of the trailer 10 by way of a torsion spindle assembly having a torsionspring 218, an arm 220 and a spindle 222. The wheels 202 movehorizontally when the support plates 212 either move toward or away fromone another. Displacement of the plurality of support plates 212 towardand away is guided through guides 224. Each guide 224 is connected tothe support base 210 and herein includes four guide supports 226.

As illustrated in FIG. 13, movement of the support plates 212 toward andaway from each other is provided by a drive actuator 248 and linkassembly 208. Link assembly 208 includes two similarly-constructed linksub-assemblies 231 a and 231 b that are mirror images of one another.The two link sub-assemblies 231 a and 231 b extend along each side of anaxis of symmetry 242. Link sub-assembly 231 a includes a link arm 236, alever arm 238, a link 236, wherein a pin 232 connects the link 236 to aslot 234 extending within the support base 210, and a drive element 251.The link arm 236 moves along with the pin 232, where the pin 232 moveswithin the slot 234. Link arm 236 is connected to the lever arm 238 byway of a pin 241, and lever arm 238 is connected to the drive link 244by way of a pin 243. Drive link 244 is connected to the drive element251. A threaded screw 250 is threadably connected to the drive element251 to form the drive actuator 248 where rotation of the threaded screw250 causes the drive element to move toward and away from the supportplate 210. It should be understood that other forms of actuators couldbe used, such as, but not limited to, hydraulic, electric and pneumaticbased actuators.

At this point it should be noted that the retractable wheel assembly 200includes a single actuating assembly. In other words, a single devicewhich when actuated causes simultaneous movement of both wheels 202inwardly or outwardly. In this embodiment, the single actuating assemblycomprises drive actuator 248.

Each lever arm 238 pivots about a stationary pivot 245. As drive link244 moves toward the support base 210, support plates 212 are pushed outor away from each other. Similarly, as drive link 244 moves away fromthe support base 210, support plates 212 are drawn in toward oneanother. When the support assembly 204 is in the extended position, linksub-assemblies 231 a and 231 b are on opposite sides of axis of symmetry242 and the lever arms 238 extend alongside the axis of symmetry 242.When the support assembly 204 is in the retracted position, link arms236 move toward each other and cross as lever arms 238 pivot in order toincrease the force applied to moving the support plates 212. FIGS. 15A,15B and 15C, illustrate movement of the link sub-assemblies 231 a and231 b. It should be noted that lever arms 238 overlap but travel inseparate, parallel planes that extend horizontally so that as lever arms238 move toward and away from one another, lever arms 238 never actuallyestablish contact.

FIGS. 15B and 16-20 further illustrate an axle locking mechanism 292.The axle locking mechanism 292 holds the support plates 212 in retractedand expanded positions. The axle locking mechanism 292 includes lockingassemblies 296 and an actuating assembly 298. Referring to FIGS. 19-20,the locking assembly 296 includes a plurality of locking devices 300such as a pin or lever connected to an actuating wire or cable 304. Alock plate 307 is secured to each of the support plates 212 and includesrecesses 318 a and 318 b to hold the support plate 212 in the retractedand expanded positions, respectively. A spring 302 can be coupled toeach locking device 300 so as to bias the locking device 300 to thelocked position, either in recess 318 a or recess 318 b.

Referring to FIGS. 16-18, the actuating assembly 298 includes an axlelock plate 305, an axle lock handle 306, a spacer 310, and a pull rod314 connecting the spacer 310 to the cable 304. In a first position,when the axle lock handle 306 is pulled, pins 300 are also pulled backagainst the bias of the springs 302. In particular, the axle lock handle306 is pulled with spacer 310 aligned with slot 316 such that spacer 310is pulled therethrough. The axle lock handle 306 can then be turned, forexample 90 degrees, so that the spacer 310 engages plate 305 because ofthe bias of the springs 302 pulling the handle 306 toward the plate 305.This will ensure that the pins 300 are held back and are prevented fromentering the recesses 318 a or 318 b. In this position of the actuatingassembly 298, the wheels 202 can be expanded or retracted. Typically, atsome point during adjustment of the wheels 202, the axle lock handle 306is turned back so as to align spacer 310 with slot 316. However, sincethe pins 300 are not aligned with either of the recesses 318 a or 318 b,the pins 300 will slide along the lock plates 307 with expansion orretraction of the wheels 202. When the pins 300 are aligned with eithernotch 318A or notch 318B due to movement of support plates 212, thespring 302 will force the pins 300 into one of notches 318A or 318B tosecure the position of the support plates 212

FIGS. 21-23 show another embodiment of a retractable wheel assembly 288with a single actuating assembly. In this embodiment, the singleactuating assembly comprises a rack-and-pinion mechanism 320 where othercomponents having the same function as the previous embodiment have beenidentified with the same reference numbers. The rack-and-pinionmechanism 320 has a circular gear 322 (also referred to as “the pinion”)and two linear gears 324A and 324B (also referred to as “racks”). Thepinion 322 is an external gear secured to rod 329, which is rotated bythe user, similar to rod 251 of the previous embodiment. The lineargears 324A and 324B are straight bars with teeth 330 on one side. Whenthe rod 329 causes rotational motion to be applied to the pinion 322,the pinion 322 rotates and the teeth of the pinion 322 engage the teethof the linear gears 324A and 324B, causing the linear gears 324A and324B to move sideways in opposite directions from one another. The endsof linear gears 324 are connected to the link arms 236, which movewithin slot openings 234. The link arms 236 are joined to the supportplates 212. Hence, as the linear gears 324 move sideways, the link arms236 also move sideways in the slot openings 234 toward or away from oneanother. As with the link assembly of the previous embodiment, therack-and-pinion mechanism 320 operates to move both wheels 202 of thetrailer 10 simultaneously in or out.

FIGS. 24-25 illustrate a variant of a pinion and rack mechanism 340where components having similar function are identified with the samereference numbers of the previous embodiments. In this embodiment, thepinion gear 322 has increased torque due to the presence of a largerdiameter drive disc, herein a gear 342 coupled thereto by a chain 344(or other endless member such as a belt) with a smaller gear 345rotating at the same speed as gear 342 by being mounted on a commonshaft. Gear 342 is driven by rotation of shaft 329 by the user throughgear 346 and chain 348. Multiple revolutions of the smaller gear 345 areneeded to cause a single revolution of the larger diameter gear 342.Advantageously the gears and chain(s), or belts and pulleys, allow theshaft 329 to be located at a higher position relative to the spindles ofthe wheels 202 so as to provide easier manipulation by the user. Statedyet another way, the drive shaft 329 is laterally offset from the piniongear 322 and disposed at a height above the support base 210 greaterthan a height of the pinion gear 322 above the support base 210.

As appreciated by those skilled in the art the endless members, hereinchains, can be removed with direct connection of the rotatable drivedisc members. It should be noted supports for the shaft 329, gear 346,gears 342, 345 and pinion gear 322 have been removed for purposes ofclearer understanding.

FIGS. 26-27 illustrate another embodiment of a retractable wheelassembly 289 with a single actuating assembly. In this embodiment, thesingle actuating assembly comprises a worm or pinion gear mechanism 332.The worm or pinion gear mechanism 332 includes a gear assembly similarto a vehicle differential that being a pinion gear connected to shaft329, which rotates a gear on each of threaded shafts 338A and 338B. Theends of shafts 338A and 338B are rotatably mounted with bearings 336Aand 336B to mounting plates 334A and 334B that are secured to portionsof the trailer 10 not shown, thus allowing shafts 338A and 338B torotate when driven by the pinion gear connected to shaft 329. The linkarms 236A and 236B are coupled to the shafts 338A and 338B via nuts 335Aand 335B, respectively, threadably mating with shafts 338A and 338B,respectively. With rotation of the shafts 338A, 338B, the nuts 335A,335B are displaced thereby moving the drive links 236A, 236B and supportplates 212 attached thereto. The worm gear mechanism 332 achieves hightorque at a low speed and causes simultaneous movement of both wheels202 inwardly or outwardly.

In one configuration shown in FIG. 28, the trailer 10 has a ski assembly252 for each wheel 202 designed to aid the trailer 10 to slide smoothlyover snow. The ski assembly 252 is joined to the trailer frame 20 by wayof a forward stabilizing link 254 pivotally fixed to a front portion ofa ski 256. An end of the forward stabilizing link 254 remote from theski 256 is removably, pivotally fixed to the trailer frame 20. The ski256 is configured to receive a tire 260 of the wheel 202. The vertical,longitudinal, and lateral movement of each tire 202 is constrained witha strap 264 extending over the top of the tire 202 in order to secure itin place. The ends of the strap 264 are connected to the ski 256. Theforward stabilizing link 254 in combination with the compliance of thetorsion supported spindle for the wheel 202, the ski 256 and the trailerframe 20 forms a four bar linkage allowing flexibility but alsoproviding sufficient rigidity. In particular, the front stabilizer link254 allows the ski 256 to flex with the torsion spindle but remainstable without excess rotation relative to the wheel axis. The forwardstabilizing link 254 inhibits the front of the ski 256 from digging intothe snow with movement of the trailer 10 over the snow.

FIG. 29 illustrates a second embodiment of a stabilizing support system283. In this embodiment lateral support members 285 (e.g. adjustable inlength) are mounted to extensions 287 that are removably, fixedlyconnected to the trailer frame 20. In the embodiment illustrated, thetrailer frame 20 includes receivers 289, each of which is configured toreceive a portion of one of the extensions 287. The stabilizing supportsystem 283 is particularly advantageous because the trailer 10 can beleveled in the folded transport position, rather than leveled after theplatforms 40 have been lowered as in the previous embodiment of FIGS. 1and 2. In addition, rather than providing support on the outer edges ofthe platforms 40, the platforms 40 can rest upon and along the length ofthe extensions 287. If desired, all or just the rear pair of lateralsupport members 285 and extensions 287 can be installed to remove atleast some of the weight off the wheels 202 during expansion and/orretraction of the retractable wheel assembly. In one embodiment, thelateral support members 285 and extensions 287 can be stored as pairs incompartments 291 provided on the outwardly facing surfaces of theprimary platforms 40.

Although the subject matter has been described in language directed tospecific environments, structural features and/or methodological acts,it is to be understood that the subject matter defined in the appendedclaims is not limited to the environments, specific features or actsdescribed above as has been held by the courts. Rather, theenvironments, specific features and acts described above are disclosedas example forms of implementing the claims.

What is claimed is:
 1. A trailer, comprising a trailer frame having ahitch; a first primary platform having a first major surface defining afirst primary plane, a first inside edge and a first outside edge, thefirst primary platform being pivotally supported by the trailer frame,the first primary platform being disposed in a first upright positionwherein the first primary platform extends upwardly from the firstinside edge with the first outside edge being elevated above the firstinside edge; and a second primary platform having a second major surfacedefining a secondary primary plane, a second inside edge and a secondoutside edge, the second primary platform being pivotally supported bythe support frame on a side opposite the first primary platform, thesecond primary platform being disposed in a second upright positionwherein the second primary platform extends upwardly from the secondinside edge with the second outside edge being elevated above the secondinside edge; and a wheel assembly comprising: a stationary support basejoined to the trailer frame; two supports slidably guided on the supportbase toward and away from each other; and a pair of wheel assemblies,wherein a wheel assembly is mounted to an end of each of the supportsremote from the other support such that a distance between the wheelassemblies varies from an extended position to a retracted position withmovement of the supports on the support base, wherein a distance betweenthe wheel assemblies in the extended position is greater than a distancebetween the wheel assemblies in the retracted position, and whereinrotatable outwardly facing surfaces of the wheel assemblies facing inopposite directions and farthest from each other in the extendedposition are disposed outboard from the first inside edge and the secondinside edge such that a distance between the outwardly facing surfacesis greater than a distance between the first inside edge and the secondinside edge.
 2. The trailer of claim 1 wherein rotatable inwardly facingsurfaces of the wheel assemblies facing toward each other and closest toeach other in the retracted position are disposed inboard from the firstinside edge and the second inside edge such that a distance between theinwardly facing surfaces is less than the distance between the firstinside edge and the second inside edge.
 3. The trailer of claim 1 andfurther comprising a locking device to selectively lock each support tothe support base in a first position where the wheel assemblies are inthe extended position and a second position where the wheel assembliesare in the retracted position.
 4. The trailer of claim 3 wherein eachlocking device comprises a member selectively engagable with a recess ineach of the first and second positions.
 5. The trailer of claim 1 andfurther comprising a drive mechanism operably joined to the supports andconfigured to selectively move the supports toward or away from eachother.
 6. The trailer of claim 1 and further comprising: a floor securedto the trailer frame between the first inside edge and the second insideedge; two wall assemblies disposed opposite each other and each wallassembly pivotally joined to the floor with a hinge, each wall assemblybeing movable from a first position wherein the wall assembly is lyingparallel to the floor to a second position where the wall assembly issubstantially perpendicular to the floor; and a canopy joined to andextending between the wall assemblies to form an enclosure when the wallassemblies are each in the second position.
 7. A trailer, comprising: atrailer frame having a hitch; a stationary support base joined to thetrailer frame; two supports slidably guided on the support base towardand away from each other; a pair of wheel assemblies, wherein a wheelassembly is mounted to an end of each of the supports remote from theother support such that a distance between the wheel assemblies varieswith movement of the supports on the support base; and a pair of lockingdevices, wherein a locking device selectively locks each support to thesupport base in a first position where the wheel assemblies are furthestfrom each other and a second position where the wheel assemblies arecloser to each other.
 8. The trailer of claim 7 wherein each lockingdevice comprises a movable member selectively engagable with a recess ineach of the first and second positions.
 9. The trailer of claim 8wherein two recesses are provided in each support and the member issecured to the frame.
 10. The trailer of claim 7 wherein each supportcomprises a plate.
 11. The trailer of claim 10 wherein each supportplate includes a guide secured thereto, each guide slidably received ina guide support secured to the support base.
 12. The trailer of claim 10wherein each support plate includes a pair of spaced apart guidessecured thereto, each guide slidably received in a guide support securedto the support base.
 13. The trailer of claim 7 wherein each supportincludes a guide secured thereto, each guide slidably received in aguide support secured to the support base.
 14. The trailer of claim 7wherein each support includes a pair of spaced apart guides securedthereto, each guide slidably received in a guide support secured to thesupport base.
 15. The trailer of claim 7 and further comprising: a firstprimary platform having a first major surface defining a first primaryplane, a first inside edge and a first outside edge, the first primaryplatform being pivotally supported by the trailer frame, the firstprimary platform being disposed in a first upright position wherein thefirst primary platform extends upwardly from the first inside edge withthe first outside edge being elevated above the first inside edge; and asecond primary platform having a second major surface defining asecondary primary plane, a second inside edge and a second outside edge,the second primary platform being pivotally supported by the supportframe on a side opposite the first primary platform, the second primaryplatform being disposed in a second upright position wherein the secondprimary platform extends upwardly from the second inside edge with thesecond outside edge being elevated above the second inside edge.
 16. Thetrailer of claim 15 and further comprising: a floor secured to thetrailer frame between the first inside edge and the second inside edge;two wall assemblies disposed opposite each other and each wall assemblypivotally joined to the floor with a hinge, each wall assembly beingmovable from a first position wherein the wall assembly is lyingparallel to the floor to a second position where the wall assembly issubstantially perpendicular to the floor; and a canopy joined to andextending between the wall assemblies to form an enclosure when the wallassemblies are each in the second position.